Haguenauer P, Berger J P, Rousselet-Perraut K, Kern P, Malbet F, Schanen-Duport I, Benech P
Appl Opt. 2000 May 1;39(13):2130-9. doi: 10.1364/ao.39.002130.
The optical characterization of a fiber-connected planar optics beam combiner dedicated to astronomical interferometry for two telescopes is presented. The beam combiner, fully integrated on a single 5 mm x 40 mm glass chip, is tested as the central part of an astronomical instrument. The single-mode waveguides are made by silver-ion-exchange technology upon glass substrates and provide spatial filtering, which improves the visibility measurement accuracy by selecting only the fundamental mode of the beams at the telescope focal plane. A global optical throughput of 43% is measured, and the sources of losses are identified and examined in detail. Solutions for improving this throughput are proposed. High and stable contrasts are obtained with a 1.55-mum laser diode (?96%) and with a white-light source (~92%) in the astronomical H filter (1.43 mum; 1.77 mum). The need for accurate control of differential instrumental polarization is demonstrated. In this context the intrinsic polarization-maintaining property of the planar optics component is characterized. This validation of the important potential uses of integrated planar optics should be valuable for future design of optical telescope arrays.
介绍了一种用于两台望远镜的天文干涉测量的光纤连接平面光学光束组合器的光学特性。该光束组合器完全集成在一个5毫米×40毫米的玻璃芯片上，作为天文仪器的核心部件进行了测试。单模波导通过玻璃基板上的银离子交换技术制成，提供空间滤波，通过仅选择望远镜焦平面上光束的基模来提高可见度测量精度。测量得到的整体光学通过率为43%，并详细识别和研究了损耗源。提出了提高该通过率的解决方案。在天文H滤光片（1.43微米；1.77微米）中，使用1.55微米激光二极管（对比度约为96%）和白光源（对比度约为92%）可获得高且稳定的对比度。证明了精确控制仪器差分偏振的必要性。在此背景下，对平面光学元件的固有保偏特性进行了表征。这种对集成平面光学重要潜在用途的验证对未来光学望远镜阵列的设计应该是有价值的。
